Those stator vanes are definitely nothing special as a design feature; it's been a common inclusion on server-grade fans as a way to smooth the airflow without resorting to thick, 76mm counter-rotating fans, and as posted by the user above, is still a major selling point for SilverStone's Air Penetrators. That said, it's also a pretty rare feature on consumer-grade fans, so credit where it's due in that regard.
I'm definitely no expert, but IIRC, in old hardcore watercooling forums of the past, old tests with server style fans with stator vanes showed they were better suited either being used with a shroud/spacer before the radiator or heatsink finstack, giving time for the airflow to smooth out and pass through the finstack "cleanly" (much like in server housings, pushing all that air through the tunnels made by the case and spacers and through the finstacks of the CPU and GPU), or in a pull config, behind filters, the radiator, or the heatsink, where the high static pressure would allow the fan to forcibly draw air through the obstruction and still "throw" it behind (again, similar to server cases, pulling all the air between the drives mounted in the front of the case, and throwing it through the "tunnels" and out the back of the server).
I'm curious if that would be the same quirks with these, given the design focus clearly inspired by server fans. The SilverStone APs also had a similar drawback in old reviews; being more useful for filtered or non-filtered intake and throwing all that air further into the case, rather than being used as a radiator or heatsink fan. In fact, SS originally marketed them strictly as case intake fans, or exhaust fans if venting up (to throw the exhaust further away from the case).